Last week, I discussed early studies on Kodiak bears, and this week I want to continue by talking about more recent research, including some troubling genetic studies.
A 1996 genetic study questioned whether Kodiak bears should be considered a separate subspecies from other Alaskan brown bears. A 1998 study on the genetic diversity of North American brown bears indicated genetic diversity among Kodiak bears is much less than it is for other populations of North American brown bears. Several of the bears sampled on Kodiak had identical genotypes. A study by Paetkau and colleagues further explored the genetic isolation of Kodiak bears from other Alaskan brown bear populations.
A 2006 report for the Kodiak National Wildlife Refuge illustrates that Kodiak bears have extremely low levels of genetic variation at neutral nuclear microsatellite markers. The level of genetic variation in Kodiak bears is much lower than the variation found in any other brown bear population. Furthermore, this low level of variation is not only found at neutral markers but also in nuclear-functional genes. While the Kodiak bear population is presently healthy, this low genetic variability makes this population susceptible to novel parasites and pathogens that may somehow reach Kodiak and infect bears.
Bear research is ongoing on the Kodiak National Wildlife Refuge. Yearly intensive aerial surveys yield population counts, and aerial stream surveys determine the number of bears on certain streams and study the population profiles of the bears on each stream (the percentage of single bears, sows with newborn cubs, sows with one-year-old cubs, etc.).
The Alaska Department of Fish and Game is studying the population characteristics and habitat use of brown bears on Afognak Island since the movements and ecology of Afognak bears are not well-understood.
In 2010, William Leacock headed a two-year project near Karluk Lake on the Kodiak National Wildlife Refuge to collar and track several Kodiak bears. Each bear in the study was fitted with a GPS collar to broadcast the bear’s location at hourly intervals. A Refuge pilot with an antenna attached to the wings of his plane flew over the bears and picked up the GPS signal from the radio collars of each bear being tracked. A crew member then downloaded these GPS points onto a laptop. From this information, the researchers were able to study the detailed movements of each bear and record the preferred habitat, food preferences, and bedding choices of each animal. Once the GPS data were collected in the field, volunteers hiked to the exact locations where each bear had been and recorded the types of food plants available in the area as well as other pertinent information. The goal of this study was to quantify behavioral responses of Kodiak bears to resources that vary in time and space (such as salmon runs and berry production). Dr. Leacock and his associates also studied how fluctuations in abundance of salmon at various streams near Karluk Lake influenced bear movements and exploitation of those streams.
Next week, I’ll discuss a new study that is both fascinating and controversial. I hope to invite the researchers on the study as well as guides who have been watching bears and their behavior for years to read my post and comment on it. Maybe I can get a lively discussion started! Be sure to check back often.
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Robin Barefield is the author of three Alaska wilderness mystery novels, Big Game, Murder Over Kodiak, and The Fisherman’s Daughter. To download a free copy of one of her novels, watch her webinar about how she became an author and why she writes Alaska wilderness mysteries. Also, sign up below to subscribe to her free, monthly newsletter on true murder and mystery in Alaska.